1. Field of the Invention
This invention relates to the fixation of nitrogen by reduction to ammonia and hydrazine. It converts elemental nitrogen, for example, gaseous nitrogen from the air, to a form useable as or in the preparation of agricultural fertilizers. It provides a way to synthesize ammonia from nitrogen and water at ambient pressures and temperatures without the use of elemental hydrogen. It also provides a method for using solar radiation in the preparation of agricultural fertilizers.
Ammonia is an important starting material in the production of nitrogen fertilizers. It is presently synthesized almost exclusively by the reaction of molecular nitrogen and hydrogen at high temperatures and pressures in the presence of an iron catalyst. The nitrogen is obtained from the air. The hydrogen is synthesized by reactions involving fossil fuels such as coal or natural gas. This invention provides a method for making ammonia which is not dependent on the use of fossil fuels.
2. Description of the Prior Art
The use of iron oxide catalyst in the synthesis of ammonia has been disclosed. U.S. Pat. No. 2,500,008 describes the synthesis of ammonia from hydrogen and nitrogen which are contacted with finely divided iron oxide catalyst and subjected to ultrasonic vibrations. However, the use of water instead of hydrogen and the use of ultraviolet light are not disclosed.
U.S. Pat. No. 3,378,475 describes the oxidation of nitrogen from air by passing air through an aqueous suspension of a catalyst such as iron oxide while irradiating with high energy ionizing radiation such as nuclear radiation, gamma rays, or x-rays. The reduction of nitrogen with the use of ultraviolet light is not described.
U.S. Pat. No. 3,925,212 describes the use of titanium dioxide as a semiconductor electrode in a solar photoelectric cell for the decomposition of water to hydrogen and oxygen.
The photoreduction of acetylene to reduced hydrocarbons with the use of titanium dioxide catalyst and ultraviolet light has been described by Boonstra and Mutsaers in the Journal of Physical Chemistry, Volume 79, page 2025 (1975).